Bovine herpesvirus-5 (DN599) antigens in cells derived from bovine ocular squamous cell carcinoma

Bovine herpesvirus 5 antigens were detected by indirect immunofluorescence in the cytoplasm of tumor cells derived from bovine ocular squamous cell carcinomas. The number of tumor cells expressing bovine herpesvirus 5 antigens was increased following exposure to ultraviolet light or maintenance in pH 8.4 media. Infectious virus could not be detected in homogenates of tumors or by explantation of tumors. However, medium removed from the ocular tumor explants induced cytoplasmic vacuolization, inclusions and syncytia when inoculated onto bovine fetal spleen monolayers. Acridine orange staining revealed these cytoplasmic inclusions to contain double-stranded deoxyribonucleic acid. These results provide evidence that bovine herpesvirus 5 may be associated with bovine ocular squamous cell carcinoma.